1. Field of the Invention
The present invention relates to improvements in the process of recovering hydrocarbons in oil wells by injection of treated inert gases obtained from industrial effluence. Particularly it refers to a process of recovering hydrocarbons in oil wells by injection of treated inert gases obtained from the process of cement clinker production.
2. Prior Art
Fossil fuels have successfully been burned in furnaces for a long time. Nevertheless, the possible reduction or minimization of air contamination is more and more being emphasized recently. In this aspect it is known that there is environmental contamination due to toxic substances. Environmental contamination also arises from substances or materials that contribute to the global warming, such as CO2 for example.
Oil well production is classified in free-flowing and artificial production. With the first, hydrocarbons gush to the outside by natural energy, which can be hydraulic pressure or the inherent gas pressure of the deposit. Artificial oil well production or oil well production by pumping is an exploitation system applied, if the inherent pressure of the deposit is not sufficient for the oil to flow up to the surface.
In the past, oil wells, which were not flowing by inherent energy, were abandoned, thus generally recovering 20% of the total reserves. With the perfection of the exploitation methods, however, the recovering of hydrocarbons found in these oil deposits was increased. Actually, if an oil well stops flowing, artificial exploiting methods are applied such as pneumatic, mechanical or hydraulic pumping.
Additionally, there exist systems, which improve the recovery by the injection of natural gas, nitrogen, carbon dioxide or water into the deposit. These systems proved to considerably increase the recovery of hydrocarbons at the deposits, making said recovering process more efficient, additionally increasing the production capacity of the deposits and allowing a reasonable exploitation of the oil resources. On the other hand, the costs for production and preparation of said gases are rather considerable.
Hydrocarbon recovery by injection of inert gases is already known for exhausted oil wells. The following patents show endeavors for its realization and as a reference their specifications are incorporated.
U.S. Pat. No. 3,873,238 with the tittle “Method and apparatus for flowing crude oil from a well” of Johnnie A. Elfarr, granted on Mar. 25th, 1975 relates to a method and apparatus for flowing crude oil from wells wherein a fluid is injected into the oil bearing earth formation for the purpose of reducing the viscosity of the oil and causing it to migrate under induced formation pressure to one or more production wells.
U.S. Pat. No. 3,892,270 with the title “Production of hydrocarbons from underground formations” of Robert H. Lindquist, granted on Jul. 1st, 1976 relates to a method for recovering hydrocarbons by injecting a mixture of oxidizing gas and steam into a lateral conduit of a hydrocarbon-containing formation to produce a product gas and, based on values contained in such gas, controlling the reactions between mixtures of oxidizing gas and steam and hydrocarbons in the formation to optimize the Kilocalories value (BTU) of the product gas.
In U.S. Pat. No. 4,267,885 with the title “Method and apparatus for optimizing production in a continuous or intermittent gas-lift well” of Dorsey W. Sanderford, granted on May 1st, 1981 the temperature of the fluid is sensed at the wellhead and used to determine the injection parameter values to optimize well production. In one embodiment, a process control unit is programmed according to the inventive method to interpret the temperature data and to control the gas control valve in order to optimize production.
U.S. Pat. No. 4,025,235 with the title “System for improving oil well production” of Joseph S. Newbrough, granted on May 24th, 1977 relates to a system utilizing intermittent build-up and release of gas pressure in the annulus between the casing and tubing in an oil well with an inert gas interface between the gas and the producing fluid.
U.S. Pat. No. 4,480,697 with the title “Method and apparatus for converting an oil well to a well with effluent raising by gas lift” of Rene F. Goldaniga, Geard Walter, G. W. Walter, Bernard J. P. Glotin and Daniel Gallois, granted on Nov. 6th, 1984 relates to a method of and apparatus for converting an oil well with natural effluent rise to one with gas-lift of the effluent column, wherein the oil well has a nipple in the production tube provided with a stop-groove and smooth bearing surfaces between which a hydraulic control line comes out.
U.S. Pat. No. 4,649,994 with the title “Installation for bringing hydrocarbon deposits into production with reinjection of effluents into the deposit or into the well or wells” of Gerard Chaudot, granted on Mar. 17th, 1987 relates to an installation for bringing into production hydrocarbon deposits with reinjection of effluents into the deposit or into the well or wells and a process for using this installation. Said installation comprises at least one sealed casing, the base of which communicates with the deposit; at least one sealing plug disposed in the lower part of the casing and forming a capacity; at least one duct for either injecting or removing a pressurized gas; a condensate injection pipe passing through the capacity and opening into the base of the casing beyond said plug, this pipe communicating with the inner volume of the casing downstream of the plug, as well as with said capacity through a valve system.
U.S. Pat. No. 5,105,889 with the title “Method of production of formation fluid and device for effecting thereof” of Taimuraz K. Misikov, Vladimir M. Shaposhnikov and Alexandr P. Skripkin granted on Apr. 21th, 1992 relates to a method of production of the formation fluid, which is used in wells with a low formation pressure. The method consists in that the gas is dissolved in the well from a flow of the formation fluid forcedly liberated, whereupon the formation fluid is transformed into a finely dispersed gas-liquid flow in which the amount of liberated gas ensures self-lift of the formation fluid to the wellhead.
WO98/20233A2 with the title “FLUID SEPARATION AND REINJECTION SYSTEMS FOR OIL WELLS” of Christopher K. Shaw published on May 14th, 1998 relates to a fluid separation and reinjection system for use in a wellbore extending through a production zone producing an oil/water mixture and a water reinjection zone, which comprises a tubing disposed within the wellbore in fluid communication with the production zone defining an oil flow channel and in fluid communication with the water reinjection zone defining a water reinjection channel.
Neither the references cited above nor the literature to the best knowledge of the inventors reveal the possibility of utilizing industrial effluence and in particular inert gases from the burning of clinker for the recovery of hydrocarbons from exhausted oil wells.